1. Field of the Invention
The invention relates to an electric cable and an electric connector and, more particularly, to an electric cable and an electric connector that are suitably used for an electrical connection in a limited wiring space.
2. Description of Related Art
There is known an existing hybrid vehicle that is equipped with an engine and a motor as a driving power source. Such a hybrid vehicle is, for example, equipped with a battery, such as a nickel metal hydride battery and a lithium ion battery. The hybrid vehicle converts direct-current voltage supplied from the battery to alternating-current voltage by an inverter and then applies the alternating-current voltage to the motor. By so doing, the hybrid vehicle is able to drive the motor for rotation to output driving power.
In the above hybrid vehicle, the inverter may be arranged in an engine compartment together with a drive unit that integrates the engine and the motor. The inverter and the motor are electrically connected to each other by electric cables. The drive unit mostly occupies a large volume in the engine compartment. Accordingly, the installation space of the inverter and the wiring space required to arrange the electric cables from the inverter to the motor may be extremely limited. Therefore, depending on the positional relationship between the inverter and the motor, more specifically, the relationship in position and orientation between the output terminals of the inverter, to which one ends of the electric cables are connected, and the input terminals of the motor, to which the other ends of the electric cables are connected, the electric cables might need to be arranged so as to be curved in an extremely narrow space.
Here, a related art document, for example, Japanese Patent Application Publication No. 2003-308738 (JP-A-2003-308738), describes an automobile wire harness. In this automobile wire harness, three electric wires are tied together by tape until a branch location, the three electric wires are separated into a set of two electric wires and a single wire and branched into two directions from the branch location, the terminal of the set of two electric wires is crimped with a single L-shaped terminal, a single L-shaped terminal is crimped with the terminal of the single electric wire, and the three electric wires are tied together by tape until the branch location to achieve branch direction control by which the two branch directions are along both right and left outer surfaces of an electric connection box and terminal direction control by which horizontal protruding portions of the two L-shaped terminals, each having a bolt hole, are located to face each other to thereby prevent the directions of the electric wires and L-shaped terminals of the wire harness branched into two directions from erroneously changing.
Incidentally, in a hybrid vehicle, mostly round electric wires are used for electric cables that connect an inverter to a motor. Each round electric wire has a copper wire and an insulating sheath material that covers the copper wire, and the copper wire and insulating sheath material have a circular cross-sectional shape. In contrast to this, a flat electric wire that has, for example, an oblong or elliptical cross-sectional shape has a larger surface area of an insulating sheath material that covers a copper wire than a round electric wire, so the flat electric wire has a relatively high heat dissipation characteristic during energization and is advantageous for suppressing a power loss due to a copper loss.
However, because the flat electric wire has a flattened cross-sectional shape having a longitudinal direction and a lateral direction, the flat electric wire is easy to bend in the lateral direction but the flat electric wire is hard to bend in the longitudinal direction. Therefore, when a flat electric wire is used for each of electric cables that connect an inverter to a motor in a hybrid vehicle, there is a problem that the flat electric wire can need to be curved in the direction in which the flat electric wire is hard to bend depending on the relationship in location, orientation, and the like, between the inverter and the motor and, therefore, the wiring space required for curving the flat electric wire increases.
Against the above problem, the automobile wire harness described in JP-A-2003-308738 is formed of three round electric wires and then prevents the directions of the set of two electric wires and single electric wire of the wire harness that are branched into two directions and the directions of the L-shaped terminals respectively crimped with the terminals of the branched set of two electric wires and single electric wire from erroneously changing. The automobile wire harness described in JP-A-2003-308738 does not provide a solution for the increased wiring space of the flat electric wire as described above.